DESCRIPTION: (Applicant's Description) The National Cancer Institute (NCI) has created a multi-institutional Cooperative Breast Cancer Tissue Resource (CBCTR) as a means of procuring and distributing archived paraffin embedded breast cancer tissues from patients with a known clinical outcome to support investigators validating potential prognostic and therapeutic markers. To date, this resource has catalogued data and tissues from 8,805 breast cancer patients. This competing continuation application describes the infrastructure created for the CBCTR since funding began in 1993. This includes the core personnel, computerized central and local databases, and tissue repositories. This application describes how registered tissues were categorized; the means of selecting, storing, and retrieving pertinent tissues; the coordination of clinical data and tissues; and the mechanism by which investigators gain access to the resource. How the tissues are prepared and distributed to researchers, as well as the quality control procedures that have been developed to achieve the goals of the resource are also outlined. The human subjects guidelines and medicolegal aspects bearing on the use of excess tissue for research are addressed. The University of Miami Jackson Memorial Hospital is an important component of this NCI-sponsored Cooperative Resource and pledges full cooperation to continue to help achieve its goals.